Method and apparatus for applying of a non-ferrous overlay on steel or steel alloy articles



June 17, 1969 P. VANSTEENKISTE' 3,449,821

METHOD AND APPARATUS FOR APPLYING OF A NON-FERROUS OVERLAY ON STEEL OR STEEL ALLOY ARTICLES Filed Dec. 25. 1966 INVENTOR. Philip Vonsieenkiste Sparrow 0nd Sparrow ATTORNEYS.

United States Patent 3,449,821 METHOD AND APPARATUS FOR APPLYING OF A NON-FERROUS OVERLAY ON STEEL OR STEEL ALLOY ARTICLES Philip Vansteenkiste, Deerlijk, Belgium, assignor to Trefileries Leon Bekaert PVBA, Swevegem, Belgium,

a corporation of Belgium Filed Dec. 23, 1966, Ser. No. 604,442 Claims priority, application Netherlands, Dec. 23, 1965, 6516868 Int. Cl. B21c 23/24 U.S. Cl. 29474.3 3 Claims ABSTRACT OF THE DISCLOSURE A method for covering of a steel or a steel alloy article, such as wire or rod; with an overlay of a non-ferrous metal by a continuous cold forming process; combined with final calibration of both steel wire and thickness of overlay; an apparatus for performing of this method.

Background of the invention The field of this invention is the cladding or coating of wire or rod made of steel or of steel alloy with a nonferrous metal, and in particular a new method of applying such overlay of a substantial thickness by mechanical means and without heat.

In the prior art, numerous methods and apparatus have been known for the so-called cladding of articles made of one material with a coating of another material. Many of these methods pertain to electro-chemical plating, others relate to welding and to hot pressing. Furthermore, all known methods refer to intermittent processes, for example covering rods, tubes or the like with a material that is different from the base material; and also to diedrawing processes, by which only the thickness of the covering is reduced.

Another process is known by which the steel (or steel alloy) parts are dipped into a bath of molten non-ferrous metal; and yet another process is known by which the steel or the steel alloy part is put into intimate contact with a finely distributed coating metal powder which subsequently is fused onto the steel by the application of heat. Preliminary treatments of the steel parts are required such as pickling in an acid bath and thoroughly rinsing with water, or by applying liquid or semi-liquid fluxes. It is a known fact that the difficulties incurred with these methods increase with the increasing thickness of the overlay, even on steel rods or tubes having a relatively short length. For example, it is not possible by all known methods to apply overlays of more than SOO-g. cadmium or aluminum per one square meter of steel or steel alloy.

This invention solves the old problem of covering or cladding of a steel (or steel alloy) wire in a continuous process by mechanical means only, by which process an inseparable molecular bonding between the steel wire and the overlay is achieved, and by which process a final calibration of both the steel wire and the thickness of the overlay is attained, without complicated preparatory treatments.

Summary The invention consists in such novel features, construction arrangements, combinations of steps and parts and improvements over the prior art as may be shown and described in connection with the method and apparatus herein disclosed by way of example only and as illustrative of a preferred embodiment.

Objects and advantages of the invention will be set forth in part hereafter and in part will be obvious herefrom or may be learned by practicing the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

It is the object of this invention to provide a method of applying an overlay on steel or steel alloy articles, such as wire or rod without requiring liquid baths, chemical treatments or applications of heat.

Another object of the invention is to provide a method of applying substantially thick overlays on steel or steel alloy wire.

Yet another object of this invention is to provide a new method of mechanically molecularly bonding of a substantial overlay of a non-ferrous metal on a steel or steel alloy wire.

A further object of the invention is to provide a method of attaining a finished product by simultaneously reducing both the diameter of the steel or steel alloy wire and the thickness of the overlay in one final step.

Furthermore, it is the object of the invention to provide a method of producing metal-clad steel or steel wire which is economical and which is performed by simple means.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawing which forms part of this specification and illustrates merely by way of example one embodiment of the invention.

In the following description and in the claims, parts will be identified by specific names for convenience, but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference characters denote like parts in the figures of the drawing, in which- Brief description of the drawing FIG. 1 shows in a schematic manner the loose application of the overlay sleeve and the adaptation thereof on the steel wire;

FIG. 2 shows the final step of bonding and reducing of the diameter of the product;

FIG. 3 shows the combination of the two steps into an in-line production.

Description of the preferred embodiment Referring now in more detail to the drawing illustrating a preferred embodiment by which the invention may be realized, there is disclosed in FIG. 1 a schematic illustration of the first step of the method of this invention and of the apparatus for this operation. The steel (or steel alloy) wire 11 is propelled by a pair of conveyor rollers 12, 13. A tubular sleeve 14 made of the overlay metal is loosely slipped over wire 11. This tubular sleeve may consist of a suitable metal, such as lead, aluminum, copper, soft brass or the like. Both sleeve 14 and wire 11 are forwarded into a first die block 15 whereby the diameter of sleeve 14 is reduced in a first step to fit more closely around steel wire 11. Immediately thereafter tubular sleeve 14 and wire 11 are drawn through the second die block 16 whereby tubular sleeve 14 now is closely fitted around wire 11. A pair of pulling rollers 17, 18 are arranged after the die blocks 15, 16 for drawing the wireoverlay combination through the dies and for conveying the obtained intermediate product 19 to a storage spool 20.

FIG. 2 shows the second step and the necessary equipment for performing the final operation. The intermediate product 19 is fed from storage spool 20 (not shown in the figure) into an elongated drawing channel 21 which may best be characterized as a stabilizing die. This stabilizing die holds the overlay over a fixed length. In this die, it is not possible that the form of the product can be modified, while the length of this stabilizing die channel is sufficient to increase artificially the friction resistance between the steel wire and the overlay in such manner as to prevent slipping or stripping of the overlay when the product will be reduced and calibrated in the final die as one element. Immediately following this stabilizing die 21, product 19 is entered into the final reducing or calibrating die 22, wherein both steel wire 11 and overlay sleeve 14 is drawn to size whereby at the same time an inseparable molecular bonding between steel wire and overlay is attained.

It is obvious that the intermediate storage spool 20 can be omitted and that a continuous in-line production can be arranged, such as it is shown in FIG. 3, which also shows the final pair of drawing rollers 23, 24 which are arranged at the end of the production line, and which convey the final product to the receiving spools (not shown in the drawing).

Production example A steel wire which is to be coated, may have a diameter of 3.6 mm. A lead tube having an inside diameter of 5.5 mm. and an outside diameter of 7.5 mm. is slipped over the wire. Drawing die block 15 has a drawing diameter of 6.5 mm., a lead-in angle of approximately 6 and an actual draw length of 2 mm. Thus, a first reduction of the lead tube from 7.6 to 6.5 mm. is obtained, followed immediately by the second drawing die block 16 wherein a second reduction to 5.6- mm. outside diameter is achieved. Obviously the inside diameter of the lead tube now is 3.6 mm. and thus closely fitting and adhering to the steel wire which has the same diameter. The overlay now has a thickness of 1 mm.

The intermediate product is fed for the second and final step into the stabilizing die 24 wherein the overlay is prevented from being stripped off the steel wire due to the increased frictional resistance between the two metals. For a product as the one described in this example, the stabilizing die 21 has to be 70 mm. long and has an entrance cone of 17 opening angle. The final outside diameter of the finished product after having passed through final die 22 is 5.2 mm. This indicates that an overall reduction of .4 mm. of the diameter had taken place, which is partly in the diameter of the steel wire, partly in the lead overlay, in'proportion of the different hardness of the two metals. Obviously the dimensions of stabilizing die vary from case to case depending upon the thickness of the overlay and upon the hardness of both the wire and the overlay materials.

While the invention has been described and illustrated with respect to a certain preferred example which gives satisfactory results, it will be understood by those skilled in the art after unnderstanding the principle of the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended in the appended claims-to cover all such changes and modifications.

What I claim is:

1. The method of applying an overlay inseparably on an elongated member consisting of a steel or steel alloy wire or rod, said overlay consisting of non-ferrous metal comprising the steps of loosely slipping a tubular sleeve consisting of said non-ferrous metal over said member, feeding said member and said sleeve together into a first die for a first reduction of the diameter of said sleeve, drawing said member and said reduced sleeve through a second die for a second reduction of the diameter of said sleeve for fitting said sleeve closely over said member without reducing the diameter of said member; feed ing said member and said fitted sleeve through an elongated stabilizing die, said die preventing said sleeve from being stripped oif said member while drawing said stabilized member and sleeve through a final die reducing simultaneously both the diameters of said member and said sleeve, thereby molecularly bonding said member and said sleeve together.

2. The method according to claim 1, and further comprising the step of intermediately re'winding and storing said member on a spool after said second reduction of the diameter of said sleeve.

3. The method according to claim 2, and further comprising the step of feeding said member and said fitted sleeve from said storage spool in a separate independent operation into said stabilizing die and through said final reducing die.

References Cited UNITED STATES PATENTS 7/1958 Nachtman et al. 29497.5 X 7/ 1963 Carlson et al 29-4975 X US. Cl. X.R. 2283 

